FieldItemInterface

class \Drupal\Core\Field\FieldItemBase extends \Drupal\Core\Field\FieldItemInterface implements \Drupal\Core\TypedData\Plugin\DataType\Map
class \Drupal\Core\Field\Plugin\Field\FieldType\BooleanItem extends \Drupal\Core\TypedData\OptionsProviderInterface implements \Drupal\Core\Field\FieldItemBase
class \Drupal\Core\Field\Plugin\Field\FieldType\ChangedItem implements \Drupal\Core\Field\Plugin\Field\FieldType\CreatedItem
class \Drupal\Core\Field\Plugin\Field\FieldType\CreatedItem implements \Drupal\Core\Field\Plugin\Field\FieldType\TimestampItem
class \Drupal\Core\Field\Plugin\Field\FieldType\DecimalItem implements \Drupal\Core\Field\Plugin\Field\FieldType\NumericItemBase
class \Drupal\Core\Field\Plugin\Field\FieldType\EmailItem implements \Drupal\Core\Field\FieldItemBase
class \Drupal\Core\Field\Plugin\Field\FieldType\EntityReferenceItem extends \Drupal\Core\TypedData\OptionsProviderInterface, \Drupal\Core\Field\PreconfiguredFieldUiOptionsInterface implements \Drupal\Core\Field\FieldItemBase
class \Drupal\Core\Field\Plugin\Field\FieldType\FloatItem implements \Drupal\Core\Field\Plugin\Field\FieldType\NumericItemBase
class \Drupal\Core\Field\Plugin\Field\FieldType\IntegerItem implements \Drupal\Core\Field\Plugin\Field\FieldType\NumericItemBase
class \Drupal\Core\Field\Plugin\Field\FieldType\LanguageItem extends \Drupal\Core\TypedData\OptionsProviderInterface implements \Drupal\Core\Field\FieldItemBase
class \Drupal\Core\Field\Plugin\Field\FieldType\MapItem implements \Drupal\Core\Field\FieldItemBase
class \Drupal\Core\Field\Plugin\Field\FieldType\NumericItemBase implements \Drupal\Core\Field\FieldItemBase
class \Drupal\Core\Field\Plugin\Field\FieldType\PasswordItem implements \Drupal\Core\Field\Plugin\Field\FieldType\StringItem
class \Drupal\Core\Field\Plugin\Field\FieldType\StringItem implements \Drupal\Core\Field\Plugin\Field\FieldType\StringItemBase
class \Drupal\Core\Field\Plugin\Field\FieldType\StringItemBase implements \Drupal\Core\Field\FieldItemBase
class \Drupal\Core\Field\Plugin\Field\FieldType\StringLongItem implements \Drupal\Core\Field\Plugin\Field\FieldType\StringItemBase
class \Drupal\Core\Field\Plugin\Field\FieldType\TimestampItem implements \Drupal\Core\Field\FieldItemBase
class \Drupal\Core\Field\Plugin\Field\FieldType\UriItem implements \Drupal\Core\Field\Plugin\Field\FieldType\StringItem
class \Drupal\Core\Field\Plugin\Field\FieldType\UuidItem implements \Drupal\Core\Field\Plugin\Field\FieldType\StringItem
class \Drupal\user\StatusItem implements \Drupal\Core\Field\Plugin\Field\FieldType\BooleanItem
class \Drupal\user\TimeZoneItem implements \Drupal\Core\Field\Plugin\Field\FieldType\StringItem
class \Drupal\user\UserNameItem implements \Drupal\Core\Field\Plugin\Field\FieldType\StringItem

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